The present invention pertains to boot technology for booting a program executed on a computer.
Generally, in computer systems equipped with a disk device, there is adopted a method wherein the Operating System (OS) of a computer is installed on a boot disk within the disk device, the boot disk is discovered at the time of starting (activating) the computer, and the operating system stored on the boot disk is booted.
As one piece of prior art, there is the method of booting from a disk built into the computer.
In this method, it is possible to boot the computer by preparing a disk device for installing the operating system in the computer in advance and installing the operating system on the same disk. Only one boot disk (the disk on which the OS to be booted is stored) exists for the computer and also, the boot disk is not shared by other computers. Consequently, it is a method with high security in which there is a low possibility that a reference or an update is carried out from another computer with respect to the boot disk.
On the other hand, there is the method of booting from an external disk array or equivalent.
A disk array possesses large-scale capacity and can connect multiple computers via a Fibre Channel and a Fibre Channel switch. In case the OS is booted from an external disk like a disk array device, there are issues with security. Disk array devices can consult or update disks inside the disk array devices from all the connected computers, basically in the same way as a network. Consequently, there is the possibility to be altered and to be referred to in the contents of the boot disk by other computers.
With respect to this issue, the disk array device uses a WWN (World Wide Name) which is a unique device identifier (ID) (also called network identity information or device identity information) stored inside a Host Bus Adapter (HBA) which is a Fibre Channel network adapter that the computer has and has the function of performing an association between the WWN possessed by some specific computer and a disk inside a disk array device. For example, it functions to restrict (limit) the range of access such that only disk 1 can be accessed from a computer 1 having a WWN1 even if the computer accesses a disk array device. A function providing this kind of zone or group is also called zoning or host grouping, and by using this zoning, it has become possible to maintain security with respect to access to disks shared between computers. This kind of technology is disclosed in U.S. Patent Application Publication No. 2004/0059816 A1.
As for the maintenance, reconfiguration and so forth of computer systems, it is common, by making an operating schedule in advance and, based on the information defined in the schedule, performing the deployment of functions (system programs: including business application and the Operating System (OS)) of computers constituting the computer system, and booting these, to have computers execute the same functions, this kind of maintenance being performed by human intervention. Regarding the contents of technology related to this kind of booting and deployment, a disclosure is made in U.S. Patent Application Publication No. 2005/0010918A1.
Generally, the boot disk settings in the computers and the security settings in the disk array have been performed by manual work of the system operations administrator, and since the WWN is modified when the computer changes, a setting of the host group in the disk array device is necessary each time, so there has been the issue that the time and the effort are necessary to operate. Moreover, even in the case that the business operations executed on the computers (system programs) are modified, since there arise modifications in the boot disks and modifications in the configuration of the disks which are the object of that processing, a modification of the host group in the disk array device becomes necessary.